ESTRO 2024 - Abstract Book

S1738

Clinical - Lung

ESTRO 2024

66.44 [52.99;67.66]

68.58 [53.75;71.04]

D 1.0ccm < 74 [Gy]

Bronchial Tree

67.22 [66.48;68.09]

70.96 [68.86;72.24]

D 1.0ccm < 74 [Gy]

Esophagus

64.42 [50.65;65.88]

65.7 [51.88;68.11]

D 1.0ccm < 70 [Gy]

Connective tissue

68.9 [68.29;69.52]

73.5 [72.87;73.84]

D 1.0ccm < 74 [Gy]

Trachea

64.67 [27.15;66.71]

65.82 [26.97;69.13]

D 1.0ccm < 74 [Gy]

Aorta

66.99 [65.41;68.03]

70.16 [67.42;72.15]

D 1.0ccm < 74 [Gy]

Chest wall

67.75 [66.55;68.54]

72.59 [69.71;73.53]

D

1.0ccm < 74 [Gy]

Spinal Cord**

42.49 [36.20;43.58]

43.12 [37.17;44.03]

D

0.05ccm < 45 [Gy]

Spinal Canal**

41.53 [31.41;45.32]

42.13 [33.62;45.54]

D

0.05ccm < 50 [Gy]

* No constraint in protocol. **Centers used either spinal cord or Spinal canal

Results:

After trial conclusion, the 350 standard plans and 350 escalated plans from five Danish and two Norwegian hospitals were analyzed. The total tumor and lymph node GTVs measured 33.6 ccm [13.1;87.8] and 12.1 ccm [4.8;28.9]. In the escalated plans, PET-GTV mean doses were 93.9 Gy [92.2;94.6] for the primary tumor sites and 73.5 Gy [73.1;73.8] for large lymph nodes. As intended, the escalated dose levels extended into the remaining target volumes, e.g. the mean dose to the tumor CTV was 80.7 Gy [77.7;83.4], see Figure 2.

OAR constraints were respected in almost all plans, see Table 1. No plans violated OAR maximum dose constraints (D1ccm/D0.05ccm) for bronchi, trachea, aorta, heart, esophagus, spinal canal/spinal cord, chest wall, or connective tissue (all mediastinal tissue not included in GTVs or other OARs). MLD and MHD were low. The median difference in MLD between each patient’s escalated and standard plan was 0.15 Gy [ -0.11;0.44]. Although no constraint was set for MHD difference between standard and escalated plans, no actual difference in MHD was observed -0.004 Gy [- 0.27;0.23].